A typical modular conveyor belt is disclosed in U.S. Pat. No. 3,870,141 issued to J. M. Lapeyre on Mar. 11, 1975. According to this patent, substantially indentical modules formed by injection molding are pivotally connected to one another to form a conveyor belt of a desired length. Each module includes a plurality of elongated elements, and each elongated element has a first pivot end and a second pivot end. The plurality of elongated elements are joined together such that the apertures defined in each of the first and second pluralities of pivot ends lie along a first and second pivot axis respectively which are parallel one to the other. The link ends of one module are intermeshed and pivotally connected by means of a pivot rod to the link ends of another module until an entire belt having the desired length is formed. Injection molded plastic belts built according to the teachings of this patent have been well received by industry and have many uses.
U.S. Pat. No. 4,171,045 issued on Oct. 16, 1979 also to J. M. Lapeyre, recognized the need for including a conveyor surface which would not allow objects riding on the conveying surface to slip and thereby allow the belt to pass underneath. A belt disclosed and constructed according to the teachings of the U.S. Pat. No. 4,171,045, is similar to that of the U.S. Pat. No. 3,870,141 patent discussed heretoforth and U.S. Pat. No. 4,051,949 also issued to Lapeyre except that selected ones of the elongated members include a plurality of "dogs" which extend above the normal portion of the conveying surface to contact and push articles on the conveying surface along such that the belt will not slip underneath.
In a similar manner, U.S. Pat. No. 4,213,527 issued June 22, 1980 to J. M. Lapeyre, et al, further discloses a module for forming a link conveyor belt which has ridges or flight members extending transverse to the direction of travel for preventing the conveyor belt from slipping under articles riding on the conveyor belt surface. Similarly U.S. Pat. No. 4,170,281 issued on Oct. 19, 1979 and U.S. Pat. No. 4,080,842 issued on Mar. 22, 1978, both to Lapeyre, also show conveying belts having members extending transverse to the conveying surface for moving articles on the conveying surface along the belt such that the belt cannot slip underneath the article. U.S. Pat. No. 4,084,687 issued Apr. 18, 1978 to J. M. Lapeyre dislcoses a conveyor belt patent not particularly relevant to the present invention wherein the top surface is resilient or flexible, and very slick.
Other modular link conveyor belt patent applications or patents by J. M. Lapeyre and/or owned by the same assignee as the present invention include:
Ser. No. 483,210 entitled "Link Chain Belt" filed Apr. 14, 1983; Ser. No. 179,523 entitled "Modular Center Drive Conveyor Belt" filed Aug. 19, 1980; and U.S. Pat. No. 4,556,142 entitled "Lightweight Modular Conveyor Belt" issued Dec. 3, 1985.
In addition, a patent application entitled "End-to-End Molded Conveyor Belt Module" filed Oct. 15, 1987 and having Ser. No. 110,109 discloses subject matter having some similarity to the present invention in that modules of certain embodiments of this invention may be "end-to-end" molded in a manner similar to that discussed in the earlier application.
A conveyor belt designed particularly for changing horizontal directions or flexing is disclosed in U.S. Pat. Nos. 4,153,152 and 4,184,588 also issued to J. M. Lapeyre on May 8, 1979 and Jan. 22, 1980 respectively.
In addition, U.S. Pat. No. 4,597,747 issued to Lapeyre on July 1, 1986 discloses a snap-together link chain which includes a center member which joins the two receiving legs of the first link end to the single post of the second link end. The center member also provides driving surfaces which cooperate with a sprocket. According to one embodiment, a multiplicity of the chain links are joined together side-by-side by a pair of integrally molded connecting members to form a wide module. However, neither of the two connecting members also function as a single bidirectional drive member, although in one embodiment the two connecting members do define a recess for receiving a driving tooth in the same manner as the Cam Clean.RTM. belts sold by The Cambridge Wire Cloth Company of Cambridge, Md. discussed below with respect to U.S. Pat. No. 4,557,374
The "All-in-One".RTM. conveyor belt manufactured by the KVP Company in Sacramento, Calif. and illustrated in FIG. 4 of U.S. Pat. No. 4,742,907 issued May 10, 1988 to Karl V. Palmaer, is a modular plastic belt driven at a central transverse connecting member which can be brick-layed, and therefore can be provided in different widths. However, this belt can be driven in only one direction, and does not include continuous elongated links which extend from pivot axis to pivot axis.
The plastic modular belt sold by the Cambridge Wire Cloth Company of Cambridge, Md. under the name of Cam-Clean.RTM. mentioned above and substantially described in U.S. Pat. No. 4,557,374 issued on Dec. 10, 1985 to Robert H. Bode is driven in the center area of a module by a sprocket tooth received by a recess in the module defined by a pair of transverse connecting members.
Thus, a review of the prior art patents and commercial belts as well as pending applications of the assignee of the present invention reveals that to date there has not been a simple and inexpensive modular conveying belt particularly designed with the unique features of this invention. More particularly, none of the prior art conveying belts are capable of being driven in both directions, have the strength of a continuous elongated link extending from pivot axis to pivot axis, and are brick-layable such that the belt can be constructed to any desired width and length. Therefore, it is an object of this invention to provide a module which can be brick-layed to construct a wide conveyor belt, and which is simple, easy to clean and inexpensive to construct and use.
It is another object of the present invention to provide a module for forming a conveyor belt which is modular and has the inherent capability of being easily repaired and replaced.
It is yet another object of the present invention to provide modules for forming a conveyor belt which is suitable for being driven in both directions.
It is also an object of the present invention to provide a conveyor belt which is simple, easy to clean, inexpensive to construct, drivable in both directions, and which can cooperate with the teeth of a comb to transfer objects to and from the belt.